The 14-member council was assembled by Finance Minister Bill Morneau to provide “bold” advice on how best to guide Canada’s struggling economy out of its slow-growth rut.

One of their first recommendations, released last week, called for a gradual increase in permanent immigration to 450,000 people a year by 2021 — with a focus on top business talent and international students. That would be a 50-per-cent hike from the current level of about 300,000.

The council members — along with many others, including Economic Development Minister Navdeep Bains — argue that opening Canada’s doors to more newcomers is a crucial ingredient for expanding growth in the future.

They say it’s particularly important as more and more of the country’s baby boomers enter their golden years, which eats away at the workforce.

The conviction to bring in more immigrants is especially significant for at least two of the people around the advisory team’s table.

Growth council chair Dominic Barton, the powerful global managing director of consulting firm McKinsey & Co., and Mark Wiseman, a senior managing director for investment management giant BlackRock Inc., are among the founders of a group dedicated to seeing the country responsibly expand its population as a way to help drive its economic potential.

The Century Initiative, a five-year-old effort by well-known Canadians, is focused on seeing the country of 36 million grow to 100 million by 2100.

Without significant policy changes on immigration, the current demographic trajectory has Canada’s population on track to reach 53 million people by the end of the century, the group says on its website. That would place it outside the top 45 nations in population size, it says.

Barton believes the demographic challenge will make Canada increasingly irrelevant over time, particularly given its already-small population size.

“Relevance is not just determined by your population, but it’s a factor given all the strengths we have,” Barton, a sought-after expert who has consulted government and business leaders around the world, said in an interview.

“Why wouldn’t we make that a strength if our diversity and multiculturalism is a strength, but it’s winnowing away as we’re getting older? Why wouldn’t we do the opposite and goose it?”

He believes Canada’s international influence would grow considerably with a bigger population. On top of that, Barton said the world would benefit from having a larger version of Canada’s stable, diversified democracy and economy.

“It’s a big number — to me, it’s more of an aspirational number,” he said when asked about the group’s goal.

“It would obviously change the country considerably. It’s a different path… But I don’t think it’s crazy.”

The discussions that eventually blossomed into Century Initiative began in 2011 during a weekend gathering of friends at Barton’s cottage in Ontario’s Muskoka region, north of Toronto.

Sitting near the edge of Lake of Bays, surrounded by the Canadian Shield, they started brainstorming about the best ways to shelter the country’s economy from the gathering, predictable demographic storm.

Barton said the first informal get-together was followed by a few other meetings, including two group treks into the High Arctic.

“We were total nerds, basically,” he said of their talks about the costs and benefits of increasing immigration.

The idea evolved and the group hired staffers and started funding research into the topic.

Barton sees a dovetail between some of the ideas behind the Century Initiative and the growth council, but he says they are separate.

In fact, behind the closed doors of the growth council meetings, Barton said the Century Initiative’s 100-million goal didn’t come up.

He did acknowledge that he and Wiseman were among the biggest proponents behind the immigration-boosting idea that the group presented to Morneau.

“Probably because Mark and I have been in (Century Initiative) we’re obviously more naturally bullish towards it,” said Barton, who also noted that there was a lot of debate on the scope of the immigration proposal.